The present invention relates to a tele-converter that is mounted on a master lens apparatus to obtain a lens system having a focal length longer than that of the master lens apparatus, and an imaging system comprising the same.
So far, there has been a rear teleconverter known in the art that comprises mounts corresponding to the mount of a master lens apparatus and the mount of a camera body, wherein a converter lens is interposed between the master lens apparatus and the camera body via those mounts to extend or elongate the focal length of the whole lens system.
Such rear teleconverters are convenient to and preferably used by those who use single-lens reflex cameras with interchangeable lenses in general and those who carry out telephotography, because of capable of making the focal length longer simply. Such rear teleconverter lenses, for instance, are set forth in Patent Publications 1 to 6.    Patent Publication 1: JP(A) 2004-226648    Patent Publication 2: JP(A) 2005-043788    Patent Publication 3: JP(A) 2005-107261    Patent Publication 4: JP(A) 2009-080176    Patent Publication 5: JP(A) 2010-191211    Patent Publication 6: JP(A) 2011-081111